1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * CAN driver for EMS Dr. Thomas Wuensche CPC-USB/ARM7
4 *
5 * Copyright (C) 2004-2009 EMS Dr. Thomas Wuensche
6 */
7 #include <linux/ethtool.h>
8 #include <linux/signal.h>
9 #include <linux/slab.h>
10 #include <linux/module.h>
11 #include <linux/netdevice.h>
12 #include <linux/usb.h>
13
14 #include <linux/can.h>
15 #include <linux/can/dev.h>
16 #include <linux/can/error.h>
17
18 MODULE_AUTHOR("Sebastian Haas <haas@ems-wuensche.com>");
19 MODULE_DESCRIPTION("CAN driver for EMS Dr. Thomas Wuensche CAN/USB interfaces");
20 MODULE_LICENSE("GPL v2");
21
22 /* Control-Values for CPC_Control() Command Subject Selection */
23 #define CONTR_CAN_MESSAGE 0x04
24 #define CONTR_CAN_STATE 0x0C
25 #define CONTR_BUS_ERROR 0x1C
26
27 /* Control Command Actions */
28 #define CONTR_CONT_OFF 0
29 #define CONTR_CONT_ON 1
30 #define CONTR_ONCE 2
31
32 /* Messages from CPC to PC */
33 #define CPC_MSG_TYPE_CAN_FRAME 1 /* CAN data frame */
34 #define CPC_MSG_TYPE_RTR_FRAME 8 /* CAN remote frame */
35 #define CPC_MSG_TYPE_CAN_PARAMS 12 /* Actual CAN parameters */
36 #define CPC_MSG_TYPE_CAN_STATE 14 /* CAN state message */
37 #define CPC_MSG_TYPE_EXT_CAN_FRAME 16 /* Extended CAN data frame */
38 #define CPC_MSG_TYPE_EXT_RTR_FRAME 17 /* Extended remote frame */
39 #define CPC_MSG_TYPE_CONTROL 19 /* change interface behavior */
40 #define CPC_MSG_TYPE_CONFIRM 20 /* command processed confirmation */
41 #define CPC_MSG_TYPE_OVERRUN 21 /* overrun events */
42 #define CPC_MSG_TYPE_CAN_FRAME_ERROR 23 /* detected bus errors */
43 #define CPC_MSG_TYPE_ERR_COUNTER 25 /* RX/TX error counter */
44
45 /* Messages from the PC to the CPC interface */
46 #define CPC_CMD_TYPE_CAN_FRAME 1 /* CAN data frame */
47 #define CPC_CMD_TYPE_CONTROL 3 /* control of interface behavior */
48 #define CPC_CMD_TYPE_CAN_PARAMS 6 /* set CAN parameters */
49 #define CPC_CMD_TYPE_RTR_FRAME 13 /* CAN remote frame */
50 #define CPC_CMD_TYPE_CAN_STATE 14 /* CAN state message */
51 #define CPC_CMD_TYPE_EXT_CAN_FRAME 15 /* Extended CAN data frame */
52 #define CPC_CMD_TYPE_EXT_RTR_FRAME 16 /* Extended CAN remote frame */
53 #define CPC_CMD_TYPE_CAN_EXIT 200 /* exit the CAN */
54
55 #define CPC_CMD_TYPE_INQ_ERR_COUNTER 25 /* request the CAN error counters */
56 #define CPC_CMD_TYPE_CLEAR_MSG_QUEUE 8 /* clear CPC_MSG queue */
57 #define CPC_CMD_TYPE_CLEAR_CMD_QUEUE 28 /* clear CPC_CMD queue */
58
59 #define CPC_CC_TYPE_SJA1000 2 /* Philips basic CAN controller */
60
61 #define CPC_CAN_ECODE_ERRFRAME 0x01 /* Ecode type */
62
63 /* Overrun types */
64 #define CPC_OVR_EVENT_CAN 0x01
65 #define CPC_OVR_EVENT_CANSTATE 0x02
66 #define CPC_OVR_EVENT_BUSERROR 0x04
67
68 /*
69 * If the CAN controller lost a message we indicate it with the highest bit
70 * set in the count field.
71 */
72 #define CPC_OVR_HW 0x80
73
74 /* Size of the "struct ems_cpc_msg" without the union */
75 #define CPC_MSG_HEADER_LEN 11
76 #define CPC_CAN_MSG_MIN_SIZE 5
77
78 /* Define these values to match your devices */
79 #define USB_CPCUSB_VENDOR_ID 0x12D6
80
81 #define USB_CPCUSB_ARM7_PRODUCT_ID 0x0444
82
83 /* Mode register NXP LPC2119/SJA1000 CAN Controller */
84 #define SJA1000_MOD_NORMAL 0x00
85 #define SJA1000_MOD_RM 0x01
86
87 /* ECC register NXP LPC2119/SJA1000 CAN Controller */
88 #define SJA1000_ECC_SEG 0x1F
89 #define SJA1000_ECC_DIR 0x20
90 #define SJA1000_ECC_ERR 0x06
91 #define SJA1000_ECC_BIT 0x00
92 #define SJA1000_ECC_FORM 0x40
93 #define SJA1000_ECC_STUFF 0x80
94 #define SJA1000_ECC_MASK 0xc0
95
96 /* Status register content */
97 #define SJA1000_SR_BS 0x80
98 #define SJA1000_SR_ES 0x40
99
100 #define SJA1000_DEFAULT_OUTPUT_CONTROL 0xDA
101
102 /*
103 * The device actually uses a 16MHz clock to generate the CAN clock
104 * but it expects SJA1000 bit settings based on 8MHz (is internally
105 * converted).
106 */
107 #define EMS_USB_ARM7_CLOCK 8000000
108
109 #define CPC_TX_QUEUE_TRIGGER_LOW 25
110 #define CPC_TX_QUEUE_TRIGGER_HIGH 35
111
112 /*
113 * CAN-Message representation in a CPC_MSG. Message object type is
114 * CPC_MSG_TYPE_CAN_FRAME or CPC_MSG_TYPE_RTR_FRAME or
115 * CPC_MSG_TYPE_EXT_CAN_FRAME or CPC_MSG_TYPE_EXT_RTR_FRAME.
116 */
117 struct cpc_can_msg {
118 __le32 id;
119 u8 length;
120 u8 msg[8];
121 };
122
123 /* Representation of the CAN parameters for the SJA1000 controller */
124 struct cpc_sja1000_params {
125 u8 mode;
126 u8 acc_code0;
127 u8 acc_code1;
128 u8 acc_code2;
129 u8 acc_code3;
130 u8 acc_mask0;
131 u8 acc_mask1;
132 u8 acc_mask2;
133 u8 acc_mask3;
134 u8 btr0;
135 u8 btr1;
136 u8 outp_contr;
137 };
138
139 /* CAN params message representation */
140 struct cpc_can_params {
141 u8 cc_type;
142
143 /* Will support M16C CAN controller in the future */
144 union {
145 struct cpc_sja1000_params sja1000;
146 } cc_params;
147 };
148
149 /* Structure for confirmed message handling */
150 struct cpc_confirm {
151 u8 error; /* error code */
152 };
153
154 /* Structure for overrun conditions */
155 struct cpc_overrun {
156 u8 event;
157 u8 count;
158 };
159
160 /* SJA1000 CAN errors (compatible to NXP LPC2119) */
161 struct cpc_sja1000_can_error {
162 u8 ecc;
163 u8 rxerr;
164 u8 txerr;
165 };
166
167 /* structure for CAN error conditions */
168 struct cpc_can_error {
169 u8 ecode;
170
171 struct {
172 u8 cc_type;
173
174 /* Other controllers may also provide error code capture regs */
175 union {
176 struct cpc_sja1000_can_error sja1000;
177 } regs;
178 } cc;
179 };
180
181 /*
182 * Structure containing RX/TX error counter. This structure is used to request
183 * the values of the CAN controllers TX and RX error counter.
184 */
185 struct cpc_can_err_counter {
186 u8 rx;
187 u8 tx;
188 };
189
190 /* Main message type used between library and application */
191 struct __packed ems_cpc_msg {
192 u8 type; /* type of message */
193 u8 length; /* length of data within union 'msg' */
194 u8 msgid; /* confirmation handle */
195 __le32 ts_sec; /* timestamp in seconds */
196 __le32 ts_nsec; /* timestamp in nano seconds */
197
198 union __packed {
199 u8 generic[64];
200 struct cpc_can_msg can_msg;
201 struct cpc_can_params can_params;
202 struct cpc_confirm confirmation;
203 struct cpc_overrun overrun;
204 struct cpc_can_error error;
205 struct cpc_can_err_counter err_counter;
206 u8 can_state;
207 } msg;
208 };
209
210 /*
211 * Table of devices that work with this driver
212 * NOTE: This driver supports only CPC-USB/ARM7 (LPC2119) yet.
213 */
214 static struct usb_device_id ems_usb_table[] = {
215 {USB_DEVICE(USB_CPCUSB_VENDOR_ID, USB_CPCUSB_ARM7_PRODUCT_ID)},
216 {} /* Terminating entry */
217 };
218
219 MODULE_DEVICE_TABLE(usb, ems_usb_table);
220
221 #define RX_BUFFER_SIZE 64
222 #define CPC_HEADER_SIZE 4
223 #define INTR_IN_BUFFER_SIZE 4
224
225 #define MAX_RX_URBS 10
226 #define MAX_TX_URBS 10
227
228 struct ems_usb;
229
230 struct ems_tx_urb_context {
231 struct ems_usb *dev;
232
233 u32 echo_index;
234 };
235
236 struct ems_usb {
237 struct can_priv can; /* must be the first member */
238
239 struct sk_buff *echo_skb[MAX_TX_URBS];
240
241 struct usb_device *udev;
242 struct net_device *netdev;
243
244 atomic_t active_tx_urbs;
245 struct usb_anchor tx_submitted;
246 struct ems_tx_urb_context tx_contexts[MAX_TX_URBS];
247
248 struct usb_anchor rx_submitted;
249
250 struct urb *intr_urb;
251
252 u8 *tx_msg_buffer;
253
254 u8 *intr_in_buffer;
255 unsigned int free_slots; /* remember number of available slots */
256
257 struct ems_cpc_msg active_params; /* active controller parameters */
258 void *rxbuf[MAX_RX_URBS];
259 dma_addr_t rxbuf_dma[MAX_RX_URBS];
260 };
261
ems_usb_read_interrupt_callback(struct urb * urb)262 static void ems_usb_read_interrupt_callback(struct urb *urb)
263 {
264 struct ems_usb *dev = urb->context;
265 struct net_device *netdev = dev->netdev;
266 int err;
267
268 if (!netif_device_present(netdev))
269 return;
270
271 switch (urb->status) {
272 case 0:
273 dev->free_slots = dev->intr_in_buffer[1];
274 if (dev->free_slots > CPC_TX_QUEUE_TRIGGER_HIGH &&
275 netif_queue_stopped(netdev))
276 netif_wake_queue(netdev);
277 break;
278
279 case -ECONNRESET: /* unlink */
280 case -ENOENT:
281 case -EPIPE:
282 case -EPROTO:
283 case -ESHUTDOWN:
284 return;
285
286 default:
287 netdev_info(netdev, "Rx interrupt aborted %d\n", urb->status);
288 break;
289 }
290
291 err = usb_submit_urb(urb, GFP_ATOMIC);
292
293 if (err == -ENODEV)
294 netif_device_detach(netdev);
295 else if (err)
296 netdev_err(netdev, "failed resubmitting intr urb: %d\n", err);
297 }
298
ems_usb_rx_can_msg(struct ems_usb * dev,struct ems_cpc_msg * msg)299 static void ems_usb_rx_can_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
300 {
301 struct can_frame *cf;
302 struct sk_buff *skb;
303 int i;
304 struct net_device_stats *stats = &dev->netdev->stats;
305
306 skb = alloc_can_skb(dev->netdev, &cf);
307 if (skb == NULL)
308 return;
309
310 cf->can_id = le32_to_cpu(msg->msg.can_msg.id);
311 cf->len = can_cc_dlc2len(msg->msg.can_msg.length & 0xF);
312
313 if (msg->type == CPC_MSG_TYPE_EXT_CAN_FRAME ||
314 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME)
315 cf->can_id |= CAN_EFF_FLAG;
316
317 if (msg->type == CPC_MSG_TYPE_RTR_FRAME ||
318 msg->type == CPC_MSG_TYPE_EXT_RTR_FRAME) {
319 cf->can_id |= CAN_RTR_FLAG;
320 } else {
321 for (i = 0; i < cf->len; i++)
322 cf->data[i] = msg->msg.can_msg.msg[i];
323
324 stats->rx_bytes += cf->len;
325 }
326 stats->rx_packets++;
327
328 netif_rx(skb);
329 }
330
ems_usb_rx_err(struct ems_usb * dev,struct ems_cpc_msg * msg)331 static void ems_usb_rx_err(struct ems_usb *dev, struct ems_cpc_msg *msg)
332 {
333 struct can_frame *cf;
334 struct sk_buff *skb;
335 struct net_device_stats *stats = &dev->netdev->stats;
336
337 skb = alloc_can_err_skb(dev->netdev, &cf);
338
339 if (msg->type == CPC_MSG_TYPE_CAN_STATE) {
340 u8 state = msg->msg.can_state;
341
342 if (state & SJA1000_SR_BS) {
343 dev->can.state = CAN_STATE_BUS_OFF;
344 if (skb)
345 cf->can_id |= CAN_ERR_BUSOFF;
346
347 dev->can.can_stats.bus_off++;
348 can_bus_off(dev->netdev);
349 } else if (state & SJA1000_SR_ES) {
350 dev->can.state = CAN_STATE_ERROR_WARNING;
351 dev->can.can_stats.error_warning++;
352 } else {
353 dev->can.state = CAN_STATE_ERROR_ACTIVE;
354 dev->can.can_stats.error_passive++;
355 }
356 } else if (msg->type == CPC_MSG_TYPE_CAN_FRAME_ERROR) {
357 u8 ecc = msg->msg.error.cc.regs.sja1000.ecc;
358 u8 txerr = msg->msg.error.cc.regs.sja1000.txerr;
359 u8 rxerr = msg->msg.error.cc.regs.sja1000.rxerr;
360
361 /* bus error interrupt */
362 dev->can.can_stats.bus_error++;
363
364 if (skb) {
365 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
366
367 switch (ecc & SJA1000_ECC_MASK) {
368 case SJA1000_ECC_BIT:
369 cf->data[2] |= CAN_ERR_PROT_BIT;
370 break;
371 case SJA1000_ECC_FORM:
372 cf->data[2] |= CAN_ERR_PROT_FORM;
373 break;
374 case SJA1000_ECC_STUFF:
375 cf->data[2] |= CAN_ERR_PROT_STUFF;
376 break;
377 default:
378 cf->data[3] = ecc & SJA1000_ECC_SEG;
379 break;
380 }
381 }
382
383 /* Error occurred during transmission? */
384 if ((ecc & SJA1000_ECC_DIR) == 0) {
385 stats->tx_errors++;
386 if (skb)
387 cf->data[2] |= CAN_ERR_PROT_TX;
388 } else {
389 stats->rx_errors++;
390 }
391
392 if (skb && (dev->can.state == CAN_STATE_ERROR_WARNING ||
393 dev->can.state == CAN_STATE_ERROR_PASSIVE)) {
394 cf->can_id |= CAN_ERR_CRTL;
395 cf->data[1] = (txerr > rxerr) ?
396 CAN_ERR_CRTL_TX_PASSIVE : CAN_ERR_CRTL_RX_PASSIVE;
397 }
398 } else if (msg->type == CPC_MSG_TYPE_OVERRUN) {
399 if (skb) {
400 cf->can_id |= CAN_ERR_CRTL;
401 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
402 }
403
404 stats->rx_over_errors++;
405 stats->rx_errors++;
406 }
407
408 if (skb)
409 netif_rx(skb);
410 }
411
412 /*
413 * callback for bulk IN urb
414 */
ems_usb_read_bulk_callback(struct urb * urb)415 static void ems_usb_read_bulk_callback(struct urb *urb)
416 {
417 struct ems_usb *dev = urb->context;
418 struct net_device *netdev;
419 int retval;
420
421 netdev = dev->netdev;
422
423 if (!netif_device_present(netdev))
424 return;
425
426 switch (urb->status) {
427 case 0: /* success */
428 break;
429
430 case -ENOENT:
431 return;
432
433 default:
434 netdev_info(netdev, "Rx URB aborted (%d)\n", urb->status);
435 goto resubmit_urb;
436 }
437
438 if (urb->actual_length > CPC_HEADER_SIZE) {
439 struct ems_cpc_msg *msg;
440 u8 *ibuf = urb->transfer_buffer;
441 u8 msg_count, start;
442
443 msg_count = ibuf[0] & ~0x80;
444
445 start = CPC_HEADER_SIZE;
446
447 while (msg_count) {
448 if (start + CPC_MSG_HEADER_LEN > urb->actual_length) {
449 netdev_err(netdev, "format error\n");
450 break;
451 }
452
453 msg = (struct ems_cpc_msg *)&ibuf[start];
454
455 switch (msg->type) {
456 case CPC_MSG_TYPE_CAN_STATE:
457 /* Process CAN state changes */
458 ems_usb_rx_err(dev, msg);
459 break;
460
461 case CPC_MSG_TYPE_CAN_FRAME:
462 case CPC_MSG_TYPE_EXT_CAN_FRAME:
463 case CPC_MSG_TYPE_RTR_FRAME:
464 case CPC_MSG_TYPE_EXT_RTR_FRAME:
465 ems_usb_rx_can_msg(dev, msg);
466 break;
467
468 case CPC_MSG_TYPE_CAN_FRAME_ERROR:
469 /* Process errorframe */
470 ems_usb_rx_err(dev, msg);
471 break;
472
473 case CPC_MSG_TYPE_OVERRUN:
474 /* Message lost while receiving */
475 ems_usb_rx_err(dev, msg);
476 break;
477 }
478
479 start += CPC_MSG_HEADER_LEN + msg->length;
480 msg_count--;
481
482 if (start > urb->actual_length) {
483 netdev_err(netdev, "format error\n");
484 break;
485 }
486 }
487 }
488
489 resubmit_urb:
490 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
491 urb->transfer_buffer, RX_BUFFER_SIZE,
492 ems_usb_read_bulk_callback, dev);
493
494 usb_anchor_urb(urb, &dev->rx_submitted);
495
496 retval = usb_submit_urb(urb, GFP_ATOMIC);
497 if (!retval)
498 return;
499
500 usb_unanchor_urb(urb);
501
502 if (retval == -ENODEV)
503 netif_device_detach(netdev);
504 else
505 netdev_err(netdev,
506 "failed resubmitting read bulk urb: %d\n", retval);
507 }
508
509 /*
510 * callback for bulk IN urb
511 */
ems_usb_write_bulk_callback(struct urb * urb)512 static void ems_usb_write_bulk_callback(struct urb *urb)
513 {
514 struct ems_tx_urb_context *context = urb->context;
515 struct ems_usb *dev;
516 struct net_device *netdev;
517
518 BUG_ON(!context);
519
520 dev = context->dev;
521 netdev = dev->netdev;
522
523 /* free up our allocated buffer */
524 usb_free_coherent(urb->dev, urb->transfer_buffer_length,
525 urb->transfer_buffer, urb->transfer_dma);
526
527 atomic_dec(&dev->active_tx_urbs);
528
529 if (!netif_device_present(netdev))
530 return;
531
532 if (urb->status)
533 netdev_info(netdev, "Tx URB aborted (%d)\n", urb->status);
534
535 netif_trans_update(netdev);
536
537 /* transmission complete interrupt */
538 netdev->stats.tx_packets++;
539 netdev->stats.tx_bytes += can_get_echo_skb(netdev, context->echo_index,
540 NULL);
541
542 /* Release context */
543 context->echo_index = MAX_TX_URBS;
544
545 }
546
547 /*
548 * Send the given CPC command synchronously
549 */
ems_usb_command_msg(struct ems_usb * dev,struct ems_cpc_msg * msg)550 static int ems_usb_command_msg(struct ems_usb *dev, struct ems_cpc_msg *msg)
551 {
552 int actual_length;
553
554 /* Copy payload */
555 memcpy(&dev->tx_msg_buffer[CPC_HEADER_SIZE], msg,
556 msg->length + CPC_MSG_HEADER_LEN);
557
558 /* Clear header */
559 memset(&dev->tx_msg_buffer[0], 0, CPC_HEADER_SIZE);
560
561 return usb_bulk_msg(dev->udev, usb_sndbulkpipe(dev->udev, 2),
562 &dev->tx_msg_buffer[0],
563 msg->length + CPC_MSG_HEADER_LEN + CPC_HEADER_SIZE,
564 &actual_length, 1000);
565 }
566
567 /*
568 * Change CAN controllers' mode register
569 */
ems_usb_write_mode(struct ems_usb * dev,u8 mode)570 static int ems_usb_write_mode(struct ems_usb *dev, u8 mode)
571 {
572 dev->active_params.msg.can_params.cc_params.sja1000.mode = mode;
573
574 return ems_usb_command_msg(dev, &dev->active_params);
575 }
576
577 /*
578 * Send a CPC_Control command to change behaviour when interface receives a CAN
579 * message, bus error or CAN state changed notifications.
580 */
ems_usb_control_cmd(struct ems_usb * dev,u8 val)581 static int ems_usb_control_cmd(struct ems_usb *dev, u8 val)
582 {
583 struct ems_cpc_msg cmd;
584
585 cmd.type = CPC_CMD_TYPE_CONTROL;
586 cmd.length = CPC_MSG_HEADER_LEN + 1;
587
588 cmd.msgid = 0;
589
590 cmd.msg.generic[0] = val;
591
592 return ems_usb_command_msg(dev, &cmd);
593 }
594
595 /*
596 * Start interface
597 */
ems_usb_start(struct ems_usb * dev)598 static int ems_usb_start(struct ems_usb *dev)
599 {
600 struct net_device *netdev = dev->netdev;
601 int err, i;
602
603 dev->intr_in_buffer[0] = 0;
604 dev->free_slots = 50; /* initial size */
605
606 for (i = 0; i < MAX_RX_URBS; i++) {
607 struct urb *urb = NULL;
608 u8 *buf = NULL;
609 dma_addr_t buf_dma;
610
611 /* create a URB, and a buffer for it */
612 urb = usb_alloc_urb(0, GFP_KERNEL);
613 if (!urb) {
614 err = -ENOMEM;
615 break;
616 }
617
618 buf = usb_alloc_coherent(dev->udev, RX_BUFFER_SIZE, GFP_KERNEL,
619 &buf_dma);
620 if (!buf) {
621 netdev_err(netdev, "No memory left for USB buffer\n");
622 usb_free_urb(urb);
623 err = -ENOMEM;
624 break;
625 }
626
627 urb->transfer_dma = buf_dma;
628
629 usb_fill_bulk_urb(urb, dev->udev, usb_rcvbulkpipe(dev->udev, 2),
630 buf, RX_BUFFER_SIZE,
631 ems_usb_read_bulk_callback, dev);
632 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
633 usb_anchor_urb(urb, &dev->rx_submitted);
634
635 err = usb_submit_urb(urb, GFP_KERNEL);
636 if (err) {
637 usb_unanchor_urb(urb);
638 usb_free_coherent(dev->udev, RX_BUFFER_SIZE, buf,
639 urb->transfer_dma);
640 usb_free_urb(urb);
641 break;
642 }
643
644 dev->rxbuf[i] = buf;
645 dev->rxbuf_dma[i] = buf_dma;
646
647 /* Drop reference, USB core will take care of freeing it */
648 usb_free_urb(urb);
649 }
650
651 /* Did we submit any URBs */
652 if (i == 0) {
653 netdev_warn(netdev, "couldn't setup read URBs\n");
654 return err;
655 }
656
657 /* Warn if we've couldn't transmit all the URBs */
658 if (i < MAX_RX_URBS)
659 netdev_warn(netdev, "rx performance may be slow\n");
660
661 /* Setup and start interrupt URB */
662 usb_fill_int_urb(dev->intr_urb, dev->udev,
663 usb_rcvintpipe(dev->udev, 1),
664 dev->intr_in_buffer,
665 INTR_IN_BUFFER_SIZE,
666 ems_usb_read_interrupt_callback, dev, 1);
667
668 err = usb_submit_urb(dev->intr_urb, GFP_KERNEL);
669 if (err) {
670 netdev_warn(netdev, "intr URB submit failed: %d\n", err);
671
672 return err;
673 }
674
675 /* CPC-USB will transfer received message to host */
676 err = ems_usb_control_cmd(dev, CONTR_CAN_MESSAGE | CONTR_CONT_ON);
677 if (err)
678 goto failed;
679
680 /* CPC-USB will transfer CAN state changes to host */
681 err = ems_usb_control_cmd(dev, CONTR_CAN_STATE | CONTR_CONT_ON);
682 if (err)
683 goto failed;
684
685 /* CPC-USB will transfer bus errors to host */
686 err = ems_usb_control_cmd(dev, CONTR_BUS_ERROR | CONTR_CONT_ON);
687 if (err)
688 goto failed;
689
690 err = ems_usb_write_mode(dev, SJA1000_MOD_NORMAL);
691 if (err)
692 goto failed;
693
694 dev->can.state = CAN_STATE_ERROR_ACTIVE;
695
696 return 0;
697
698 failed:
699 netdev_warn(netdev, "couldn't submit control: %d\n", err);
700
701 return err;
702 }
703
unlink_all_urbs(struct ems_usb * dev)704 static void unlink_all_urbs(struct ems_usb *dev)
705 {
706 int i;
707
708 usb_unlink_urb(dev->intr_urb);
709
710 usb_kill_anchored_urbs(&dev->rx_submitted);
711
712 for (i = 0; i < MAX_RX_URBS; ++i)
713 usb_free_coherent(dev->udev, RX_BUFFER_SIZE,
714 dev->rxbuf[i], dev->rxbuf_dma[i]);
715
716 usb_kill_anchored_urbs(&dev->tx_submitted);
717 atomic_set(&dev->active_tx_urbs, 0);
718
719 for (i = 0; i < MAX_TX_URBS; i++)
720 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
721 }
722
ems_usb_open(struct net_device * netdev)723 static int ems_usb_open(struct net_device *netdev)
724 {
725 struct ems_usb *dev = netdev_priv(netdev);
726 int err;
727
728 err = ems_usb_write_mode(dev, SJA1000_MOD_RM);
729 if (err)
730 return err;
731
732 /* common open */
733 err = open_candev(netdev);
734 if (err)
735 return err;
736
737 /* finally start device */
738 err = ems_usb_start(dev);
739 if (err) {
740 if (err == -ENODEV)
741 netif_device_detach(dev->netdev);
742
743 netdev_warn(netdev, "couldn't start device: %d\n", err);
744
745 close_candev(netdev);
746
747 return err;
748 }
749
750
751 netif_start_queue(netdev);
752
753 return 0;
754 }
755
ems_usb_start_xmit(struct sk_buff * skb,struct net_device * netdev)756 static netdev_tx_t ems_usb_start_xmit(struct sk_buff *skb, struct net_device *netdev)
757 {
758 struct ems_usb *dev = netdev_priv(netdev);
759 struct ems_tx_urb_context *context = NULL;
760 struct net_device_stats *stats = &netdev->stats;
761 struct can_frame *cf = (struct can_frame *)skb->data;
762 struct ems_cpc_msg *msg;
763 struct urb *urb;
764 u8 *buf;
765 int i, err;
766 size_t size = CPC_HEADER_SIZE + CPC_MSG_HEADER_LEN
767 + sizeof(struct cpc_can_msg);
768
769 if (can_dev_dropped_skb(netdev, skb))
770 return NETDEV_TX_OK;
771
772 /* create a URB, and a buffer for it, and copy the data to the URB */
773 urb = usb_alloc_urb(0, GFP_ATOMIC);
774 if (!urb)
775 goto nomem;
776
777 buf = usb_alloc_coherent(dev->udev, size, GFP_ATOMIC, &urb->transfer_dma);
778 if (!buf) {
779 netdev_err(netdev, "No memory left for USB buffer\n");
780 usb_free_urb(urb);
781 goto nomem;
782 }
783
784 msg = (struct ems_cpc_msg *)&buf[CPC_HEADER_SIZE];
785
786 msg->msg.can_msg.id = cpu_to_le32(cf->can_id & CAN_ERR_MASK);
787 msg->msg.can_msg.length = cf->len;
788
789 if (cf->can_id & CAN_RTR_FLAG) {
790 msg->type = cf->can_id & CAN_EFF_FLAG ?
791 CPC_CMD_TYPE_EXT_RTR_FRAME : CPC_CMD_TYPE_RTR_FRAME;
792
793 msg->length = CPC_CAN_MSG_MIN_SIZE;
794 } else {
795 msg->type = cf->can_id & CAN_EFF_FLAG ?
796 CPC_CMD_TYPE_EXT_CAN_FRAME : CPC_CMD_TYPE_CAN_FRAME;
797
798 for (i = 0; i < cf->len; i++)
799 msg->msg.can_msg.msg[i] = cf->data[i];
800
801 msg->length = CPC_CAN_MSG_MIN_SIZE + cf->len;
802 }
803
804 for (i = 0; i < MAX_TX_URBS; i++) {
805 if (dev->tx_contexts[i].echo_index == MAX_TX_URBS) {
806 context = &dev->tx_contexts[i];
807 break;
808 }
809 }
810
811 /*
812 * May never happen! When this happens we'd more URBs in flight as
813 * allowed (MAX_TX_URBS).
814 */
815 if (!context) {
816 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
817 usb_free_urb(urb);
818
819 netdev_warn(netdev, "couldn't find free context\n");
820
821 return NETDEV_TX_BUSY;
822 }
823
824 context->dev = dev;
825 context->echo_index = i;
826
827 usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, 2), buf,
828 size, ems_usb_write_bulk_callback, context);
829 urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
830 usb_anchor_urb(urb, &dev->tx_submitted);
831
832 can_put_echo_skb(skb, netdev, context->echo_index, 0);
833
834 atomic_inc(&dev->active_tx_urbs);
835
836 err = usb_submit_urb(urb, GFP_ATOMIC);
837 if (unlikely(err)) {
838 can_free_echo_skb(netdev, context->echo_index, NULL);
839
840 usb_unanchor_urb(urb);
841 usb_free_coherent(dev->udev, size, buf, urb->transfer_dma);
842
843 atomic_dec(&dev->active_tx_urbs);
844
845 if (err == -ENODEV) {
846 netif_device_detach(netdev);
847 } else {
848 netdev_warn(netdev, "failed tx_urb %d\n", err);
849
850 stats->tx_dropped++;
851 }
852 } else {
853 netif_trans_update(netdev);
854
855 /* Slow down tx path */
856 if (atomic_read(&dev->active_tx_urbs) >= MAX_TX_URBS ||
857 dev->free_slots < CPC_TX_QUEUE_TRIGGER_LOW) {
858 netif_stop_queue(netdev);
859 }
860 }
861
862 /*
863 * Release our reference to this URB, the USB core will eventually free
864 * it entirely.
865 */
866 usb_free_urb(urb);
867
868 return NETDEV_TX_OK;
869
870 nomem:
871 dev_kfree_skb(skb);
872 stats->tx_dropped++;
873
874 return NETDEV_TX_OK;
875 }
876
ems_usb_close(struct net_device * netdev)877 static int ems_usb_close(struct net_device *netdev)
878 {
879 struct ems_usb *dev = netdev_priv(netdev);
880
881 /* Stop polling */
882 unlink_all_urbs(dev);
883
884 netif_stop_queue(netdev);
885
886 /* Set CAN controller to reset mode */
887 if (ems_usb_write_mode(dev, SJA1000_MOD_RM))
888 netdev_warn(netdev, "couldn't stop device");
889
890 close_candev(netdev);
891
892 return 0;
893 }
894
895 static const struct net_device_ops ems_usb_netdev_ops = {
896 .ndo_open = ems_usb_open,
897 .ndo_stop = ems_usb_close,
898 .ndo_start_xmit = ems_usb_start_xmit,
899 };
900
901 static const struct ethtool_ops ems_usb_ethtool_ops = {
902 .get_ts_info = ethtool_op_get_ts_info,
903 };
904
905 static const struct can_bittiming_const ems_usb_bittiming_const = {
906 .name = KBUILD_MODNAME,
907 .tseg1_min = 1,
908 .tseg1_max = 16,
909 .tseg2_min = 1,
910 .tseg2_max = 8,
911 .sjw_max = 4,
912 .brp_min = 1,
913 .brp_max = 64,
914 .brp_inc = 1,
915 };
916
ems_usb_set_mode(struct net_device * netdev,enum can_mode mode)917 static int ems_usb_set_mode(struct net_device *netdev, enum can_mode mode)
918 {
919 struct ems_usb *dev = netdev_priv(netdev);
920
921 switch (mode) {
922 case CAN_MODE_START:
923 if (ems_usb_write_mode(dev, SJA1000_MOD_NORMAL))
924 netdev_warn(netdev, "couldn't start device");
925
926 if (netif_queue_stopped(netdev))
927 netif_wake_queue(netdev);
928 break;
929
930 default:
931 return -EOPNOTSUPP;
932 }
933
934 return 0;
935 }
936
ems_usb_set_bittiming(struct net_device * netdev)937 static int ems_usb_set_bittiming(struct net_device *netdev)
938 {
939 struct ems_usb *dev = netdev_priv(netdev);
940 struct can_bittiming *bt = &dev->can.bittiming;
941 u8 btr0, btr1;
942
943 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
944 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
945 (((bt->phase_seg2 - 1) & 0x7) << 4);
946 if (dev->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
947 btr1 |= 0x80;
948
949 netdev_info(netdev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
950
951 dev->active_params.msg.can_params.cc_params.sja1000.btr0 = btr0;
952 dev->active_params.msg.can_params.cc_params.sja1000.btr1 = btr1;
953
954 return ems_usb_command_msg(dev, &dev->active_params);
955 }
956
init_params_sja1000(struct ems_cpc_msg * msg)957 static void init_params_sja1000(struct ems_cpc_msg *msg)
958 {
959 struct cpc_sja1000_params *sja1000 =
960 &msg->msg.can_params.cc_params.sja1000;
961
962 msg->type = CPC_CMD_TYPE_CAN_PARAMS;
963 msg->length = sizeof(struct cpc_can_params);
964 msg->msgid = 0;
965
966 msg->msg.can_params.cc_type = CPC_CC_TYPE_SJA1000;
967
968 /* Acceptance filter open */
969 sja1000->acc_code0 = 0x00;
970 sja1000->acc_code1 = 0x00;
971 sja1000->acc_code2 = 0x00;
972 sja1000->acc_code3 = 0x00;
973
974 /* Acceptance filter open */
975 sja1000->acc_mask0 = 0xFF;
976 sja1000->acc_mask1 = 0xFF;
977 sja1000->acc_mask2 = 0xFF;
978 sja1000->acc_mask3 = 0xFF;
979
980 sja1000->btr0 = 0;
981 sja1000->btr1 = 0;
982
983 sja1000->outp_contr = SJA1000_DEFAULT_OUTPUT_CONTROL;
984 sja1000->mode = SJA1000_MOD_RM;
985 }
986
987 /*
988 * probe function for new CPC-USB devices
989 */
ems_usb_probe(struct usb_interface * intf,const struct usb_device_id * id)990 static int ems_usb_probe(struct usb_interface *intf,
991 const struct usb_device_id *id)
992 {
993 struct net_device *netdev;
994 struct ems_usb *dev;
995 int i, err = -ENOMEM;
996
997 netdev = alloc_candev(sizeof(struct ems_usb), MAX_TX_URBS);
998 if (!netdev) {
999 dev_err(&intf->dev, "ems_usb: Couldn't alloc candev\n");
1000 return -ENOMEM;
1001 }
1002
1003 dev = netdev_priv(netdev);
1004
1005 dev->udev = interface_to_usbdev(intf);
1006 dev->netdev = netdev;
1007
1008 dev->can.state = CAN_STATE_STOPPED;
1009 dev->can.clock.freq = EMS_USB_ARM7_CLOCK;
1010 dev->can.bittiming_const = &ems_usb_bittiming_const;
1011 dev->can.do_set_bittiming = ems_usb_set_bittiming;
1012 dev->can.do_set_mode = ems_usb_set_mode;
1013 dev->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
1014
1015 netdev->netdev_ops = &ems_usb_netdev_ops;
1016 netdev->ethtool_ops = &ems_usb_ethtool_ops;
1017
1018 netdev->flags |= IFF_ECHO; /* we support local echo */
1019
1020 init_usb_anchor(&dev->rx_submitted);
1021
1022 init_usb_anchor(&dev->tx_submitted);
1023 atomic_set(&dev->active_tx_urbs, 0);
1024
1025 for (i = 0; i < MAX_TX_URBS; i++)
1026 dev->tx_contexts[i].echo_index = MAX_TX_URBS;
1027
1028 dev->intr_urb = usb_alloc_urb(0, GFP_KERNEL);
1029 if (!dev->intr_urb)
1030 goto cleanup_candev;
1031
1032 dev->intr_in_buffer = kzalloc(INTR_IN_BUFFER_SIZE, GFP_KERNEL);
1033 if (!dev->intr_in_buffer)
1034 goto cleanup_intr_urb;
1035
1036 dev->tx_msg_buffer = kzalloc(CPC_HEADER_SIZE +
1037 sizeof(struct ems_cpc_msg), GFP_KERNEL);
1038 if (!dev->tx_msg_buffer)
1039 goto cleanup_intr_in_buffer;
1040
1041 usb_set_intfdata(intf, dev);
1042
1043 SET_NETDEV_DEV(netdev, &intf->dev);
1044
1045 init_params_sja1000(&dev->active_params);
1046
1047 err = ems_usb_command_msg(dev, &dev->active_params);
1048 if (err) {
1049 netdev_err(netdev, "couldn't initialize controller: %d\n", err);
1050 goto cleanup_tx_msg_buffer;
1051 }
1052
1053 err = register_candev(netdev);
1054 if (err) {
1055 netdev_err(netdev, "couldn't register CAN device: %d\n", err);
1056 goto cleanup_tx_msg_buffer;
1057 }
1058
1059 return 0;
1060
1061 cleanup_tx_msg_buffer:
1062 kfree(dev->tx_msg_buffer);
1063
1064 cleanup_intr_in_buffer:
1065 kfree(dev->intr_in_buffer);
1066
1067 cleanup_intr_urb:
1068 usb_free_urb(dev->intr_urb);
1069
1070 cleanup_candev:
1071 free_candev(netdev);
1072
1073 return err;
1074 }
1075
1076 /*
1077 * called by the usb core when the device is removed from the system
1078 */
ems_usb_disconnect(struct usb_interface * intf)1079 static void ems_usb_disconnect(struct usb_interface *intf)
1080 {
1081 struct ems_usb *dev = usb_get_intfdata(intf);
1082
1083 usb_set_intfdata(intf, NULL);
1084
1085 if (dev) {
1086 unregister_netdev(dev->netdev);
1087
1088 unlink_all_urbs(dev);
1089
1090 usb_free_urb(dev->intr_urb);
1091
1092 kfree(dev->intr_in_buffer);
1093 kfree(dev->tx_msg_buffer);
1094
1095 free_candev(dev->netdev);
1096 }
1097 }
1098
1099 /* usb specific object needed to register this driver with the usb subsystem */
1100 static struct usb_driver ems_usb_driver = {
1101 .name = KBUILD_MODNAME,
1102 .probe = ems_usb_probe,
1103 .disconnect = ems_usb_disconnect,
1104 .id_table = ems_usb_table,
1105 };
1106
1107 module_usb_driver(ems_usb_driver);
1108